body,
div,
dl,
dt,
dd,
ul,
ol,
li,
h1,
h2,
h3,
h4,
h5,
h6,
pre,
code,
form,
fieldset,
legend,
input,
button,
textarea,
p,
blockquote,
th,
hr,
td {
	margin: 0;
	padding: 0;
	-webkit-box-sizing: border-box;
	-moz-box-sizing: border-box;
	box-sizing: border-box;
}

*::before{
  box-sizing: border-box;
}
*::after{
  box-sizing: border-box;
}

.html-mode {
  animation: flip 2s;
  -webkit-animation: flip 2s;
}
  
@keyframes flip {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@-webkit-keyframes flip {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}